|BRIEF RESEARCH ARTICLE
|Year : 2022 | Volume
| Issue : 4 | Page : 512-515
Significance of Laboratory Markers in Predicting the Severity of COVID-19 in the Central Reserve Police Force Front-line Workers with a Review of Literature
CH Krishna Reddy1, PK Achari2, B Nisha3, AR Radha2
1 Specialist Medical Officer, Department of Pathology and Laboratory Medicine, Composite Hospital, CRPF, Hyderabad, Telangana, India
2 Medical Officer, Department of Medicine, Composite Hospital, CRPF, Hyderabad, Telangana, India
3 Specialist Medical Officer, Department of Obstetrics and Gynecology, Composite Hospital, CRPF, Hyderabad, Telangana, India
|Date of Submission||01-Jul-2021|
|Date of Decision||14-Oct-2022|
|Date of Acceptance||21-Oct-2022|
|Date of Web Publication||31-Dec-2022|
C H Krishna Reddy
Matrusri Nagar, Hyderabad, Telangana
Source of Support: None, Conflict of Interest: None
| Abstract|| |
COVID-19 disease has variable clinical presentations, ranging from asymptomatic to mild symptoms to severe manifestation with pneumonia, acute respiratory distress syndrome, septic shock, disseminated intravascular coagulation, and/or multiple organ failure. The real-time reverse transcription–polymerase chain reaction is gold standard test for severe acute respiratory syndrome-coronavirus-2 detection. In the present study, we aimed to predict the significance of various hematological and biochemical markers for early identification of complications and assessing the severity of the disease. A total of cases were divided into two study groups, namely, severe and nonsevere based on clinical presentation. Out of 210 cases, 186 (88.5%) cases were nonsevere and 24 (11.5%) cases were severe. Among various hematological and biochemical markers studied, hemoglobin, total leukocyte count, neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, albumin, lactate dehydrogenase, C-reactive protein, ferritin, D-dimer, and interleukin-6 are found to have P < 0.05 and significantly correlated with the severity of disease.
Keywords: COVID-19, Central Reserve Police Force, severe acute respiratory syndrome-coronavirus-2, severe
|How to cite this article:|
Krishna Reddy C H, Achari P K, Nisha B, Radha A R. Significance of Laboratory Markers in Predicting the Severity of COVID-19 in the Central Reserve Police Force Front-line Workers with a Review of Literature. Indian J Public Health 2022;66:512-5
|How to cite this URL:|
Krishna Reddy C H, Achari P K, Nisha B, Radha A R. Significance of Laboratory Markers in Predicting the Severity of COVID-19 in the Central Reserve Police Force Front-line Workers with a Review of Literature. Indian J Public Health [serial online] 2022 [cited 2023 Feb 4];66:512-5. Available from: https://www.ijph.in/text.asp?2022/66/4/512/366567
| Introduction|| |
In December 2019, a disease caused by a novel human coronavirus, called severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) was first identified in the city of Wuhan in Hubei province, China. The COVID-19 disease has variable clinical presentations, ranging from asymptomatic or mild symptoms in most patients (up to 80%) to severe manifestation with pneumonia, acute respiratory distress syndrome, septic shock, disseminated intravascular coagulation, and/or multiple organ failure. Laboratory diagnosis of COVID-19 includes real-time reverse transcription–polymerase chain reaction (RT-PCR), which is based on the detection of the nuclei acid specific to the SARS-CoV-2, or by SARS-CoV-2 antigen detection by rapid immunochromatographic assay in upper respiratory tract specimens. In cases where RT-PCR is false negative, computed tomography of the chest is increasingly recognized as strong evidence for early diagnosis.
The Central Reserve Police Force (CRPF) is one of the largest paramilitary forces in the world and due to the varied duties performed by the force, there are high chances of COVID-19 infection among the force personnel; hence, in the present study, we aimed to predict the significance of various hematological and biochemical biomarkers in COVID-19 for early identification of complications and assessing the severity of the disease among the front-line workers of the country.
The study was conducted retrospectively for 1 year from June 2020 to May 2021 at Composite Hospital, CRPF, Avadi. A total of 210 cases admitted to the hospital due to COVID-19 were studied.
All COVID-19 cases confirmed by RT-PCR on nasopharyngeal and oropharyngeal swabs cases included both force personnel and their dependents.
Suspected cases with negative RT-PCR and cases with incomplete data were excluded from the study.
Patient's demographic data such as age, sex, clinical presenting symptoms, and comorbidities were collected. Vitals such as body temperature, heart rate, respiratory rate (RR), blood pressure, and peripheral venous blood oxygen saturation (SpO2) value were recorded at the time of admission. Based on RR and blood SpO2 levels, total cases were divided into two study groups, namely, severe and nonsevere for comparison. The severe group included cases with RR ≥24 breaths per minute and/or blood oxygen saturation ≤93%. All the remaining cases not meeting the above criteria were classified as the nonsevere group. Blood samples were collected and subjected to routine testing of hemoglobin, total leukocyte counts, neutrophil count, lymphocyte count, and platelet count, and with this neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) was calculated. Routine biochemical tests such as creatinine, total bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), and albumin were performed in all cases. Special investigations such as C-reactive protein (CRP), D-dimer, ferritin, lactate dehydrogenase (LDH), and prothrombin time (PT) were performed in all cases of the severe group and in few cases of the nonsevere group.
Out of 210 cases, 186 (88.5%) cases were nonsevere and 24 (11.5%) cases were severe. Of these, 197 (94%) cases were male and 13 (6%) cases were female. The minimum age was 8 years and the maximum age was 72 years with mean of 41 years. The mean ages for severe and nonsevere cases were 50 and 40 years, respectively. Most of them were asymptomatic in 94 cases and symptomatic in 116 cases [Table 1]. Comorbidities were seen in 20% (42 cases) of all cases, 46% among severe cases, and 17% among nonsevere cases; of these, diabetes mellitus and hypertension were commonly seen.
Among the hematological markers studied, the hemoglobin values were in range of 8.3–20.5 g/dl with mean value of 14.4 g/dl. Total leukocyte count was in range of 1.4–19.6 × 109/L with mean value of 6.3 × 109/L. The total neutrophil count was in range of 0.9–16.7 × 109/L with mean value of 3.8 × 109/L. Total lymphocyte count was in range of 0.4–4.5 × 109/L with mean value of 2.0 × 109/L. NLR ratio was in range of 0.6–12.8 with mean of 2.2. Platelets were in range of 80–440 × 109/L, with mean value of 222 × 109/L. PLR ratio was in range of 32–515 with mean of 124. PT was in range of 12.9–39.3 s with mean of 15.9 sec. Among the biochemical markers studied, creatinine was in range of 0.3–7.7 mg/dl with mean of 0.94 mg/dl. Total bilirubin was in range of 0.3–3.9 mg/dl with mean of 0.96 mg/dl. Albumin was in range of 1.2–6.8 gm/dl with mean of 4.0 gm/dl. The AST values were in range of 16–207 U/L with mean of 35 U/L. The ALT values were in range of 10–100 U/L with mean of 30 U/L. The LDH values were in range of 147–653 U/L with mean of 366 U/L. CRP was positive in 96% of the severe group and 11% of the nonsevere group. Ferritin was in range of 12–1852 ng/ml with mean of 457 ng/ml. D-dimer was in range of 0.06–25.5 μg/ml with mean of 1.8 μg/ml. Interleukin (IL)-6 in the severe group was in range of 1.5–43.4 pg/ml with mean of 20.8 pg/ml [Table 2].
|Table 2: Comparison of hematological and biochemical markers in both groups|
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| Discussion|| |
SARS-CoV-2 is the third type of coronavirus detected in the past two decades after SARS-CoV-1 with a fatality rate of ~10% and Middle East respiratory syndrome-CoV with a fatality rate of ~38%, identified in 2003–2012, respectively. In the present study of 210 cases, severe cases were 24 (11.5%) and nonsevere cases were 186 (88.5%). In the present study, we have reported that there is a significant increase in leukocyte and neutrophil count in severe cases with P = 0.007 and P = 0.001, respectively, which was in concordance with a study done by Yang et al. According to most studies conducted on COVID patients, lymphocytes were significantly lower in severe cases when compared to mild/moderate cases, which was also observed in our study indicated by P = 0.001. NLR encompasses two types of leukocyte subtypes, and by measuring the neutrophil and lymphocyte levels, it reflects the balance between the severity of the inflammation and the immunity status. NLR is easy to calculate, cost-effective, and consistently high in severe cases. Pimentel et al. reported that NLR >3.3 is independently associated with more severe COVID-19. PLR, like NLR, is more accurate and reliable and is utilized as an effective inflammatory mediator in predicting the prognosis and severity in COVID patients. In our study, PLR is significantly high in the severe group with P = 0.001. In our study, the AST and ALT were higher in the severe group than the nonsevere group; this was in concordance with other similar studies. CRP is a nonspecific acute phase reactant plasma protein that is synthesized by the liver and induced by different inflammatory mediators such as IL-6. In our study, CRP was positive in 96% of cases of the severe group and 11% of cases of the nonsevere group, which clearly shows its elevation in severe cases. Despite being nonspecific, CRP is used clinically as a biomarker for different inflammatory conditions, and an increase in its levels is associated with greater severity of the disease. In our study, D-dimer was significantly higher among the severe group than in the nonsevere with P = 0.03. Based on our study, we recommend D-dimer as one of the most effective biomarkers along with LDH, CRP, and ferritin in predicting the mortality of disease; this is further augmented as treatment with anticoagulants led to a decrease in D-dimer and CRP levels in patients with good clinical prognosis. IL-6 is the most common type of cytokine released by activated macrophages during cytokine release syndrome. Our study showed significantly elevated IL-6 levels in almost all cases of the severe group with a mean of 20.8 pg/ml; it clearly indicates that IL-6 plays a major role in the activation of the immune system, leading to widespread damage in severe COVID-19 patients. Observation from our study and several other studies shows that total leukocyte count, neutrophil count, lymphocyte count, NLR, PLR, AST, ALT, creatinine, albumin, LDH, CRP, ferritin, D-dimer, and IL-6 should be used as an early marker for estimating the severity and prognosis of the disease [Table 2]. With the help of these hematological and biochemical markers evaluated in the present study, severe patients with rapid progression of disease were identified early and aggressive treatment with anti-inflammatory drugs and anticoagulants has prevented mortality, reduced oxygen requirement, and shortened hospital stay of the patients.
In conclusion, the diagnosis of COVID-19 is based on clinical signs and symptoms and confirmed by RT-PCR, which is considered the gold standard test for SARS-CoV-2 detection. From our study, we recommend estimation of hemoglobin, total leukocyte count, neutrophil count, lymphocyte count, NLR, PLR, albumin, LDH, CRP, ferritin, D-dimer, and IL-6 values, especially NLR and lymphocyte counts, as these are easily available, cost-effective, and consistent, in all COVID patients admitted to the hospital.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]